I'm a grapefruit fan who just recently experienced eating pomelo (Chinese grapefruit) for the first time. I must say it was sweeter than most any grapefruit I've ever had. Pomelos are plentiful and cheap in the markets right now.
Coffee and prime rib seem like unlikely partners, but Ryan Farr's recipe reveals they both have an earthy quality that makes them a natural match. Just be sure to scrape off any excess coffee rub from the meat before serving.